download_RStudio_CRAN_data: Download RStudio CRAN mirror data files into a folder

Description

This function download these files based on the code from the download page (http://cran-logs.rstudio.com/) into a temporary folder.

Usage

download_RStudio_CRAN_data(
  START = as.Date(Sys.time()) - 5,
  END = as.Date(Sys.time()),
  log_folder = tempdir(),
  trunc_END_date_to_today = TRUE,
  override = FALSE,
  message = TRUE,
  ...
)

Value

Returns the value of log_folder.

Arguments

START: the defaults is 5 days before today. A character string of the START date for files to be downloaded. The date format is "YYYY-MM-DD".
END: the defaults is today. A character string of the END date for files to be downloaded. The date format is "YYYY-MM-DD".
log_folder: the folder into which we would like the files to be downloaded to. Default is the temporary folder picked by tempdir.
trunc_END_date_to_today: default is TRUE. Makes sure that if END date is later then today, the END date will be change to today (since otherwise, we will only get many 404 errors)
override: boolean (default is FALSE) - should the function download files that are already available in the temp folder
message: boolean (default is TRUE) - should a message be printed in interesting cases.
...: not in use.

Details

RStudio maintains its own CRAN mirror, https://cran.rstudio.com/ and offers its log files.

Examples

Run this code

if (FALSE) {
# The first two functions might take a good deal of time to run (depending on the date range)
RStudio_CRAN_data_folder <- 
      download_RStudio_CRAN_data(START = '2013-04-02',
                                 END = '2013-04-05') 
                                 # around the time R 3.0.0 was released
# RStudio_CRAN_data_folder <- download_RStudio_CRAN_data()
my_RStudio_CRAN_data <- read_RStudio_CRAN_data(RStudio_CRAN_data_folder)

# barplots: (more functions can easily be added in the future)
barplot_package_users_per_day("installr", my_RStudio_CRAN_data)
barplot_package_users_per_day("plyr", my_RStudio_CRAN_data)
}